1. Field of the Invention
The present invention relates to the process for manufacturing a set of decorative panels provided with a decor which is matching over two opposite edges of the panels when the panels are arranged in a predetermined order.
2. Description of Related Prior Art
Panels coated with thermosetting laminates have been present on the market for some time now. They are foremost used where the demand for abrasion resistance is high, but also where resistance towards different chemicals and moisture is required. As an example of such products floors, floor beadings, table tops, work tops and wall panels can be mentioned.
The thermosetting laminate mostly consists of a base layer with a decor sheet placed closest to the surface. The decor sheet can be provided with a desired decor or pattern. The most frequent patterns usually represent the image of different kinds of wood, or minerals such as marble or granite. The surface of the laminate can be provided with a structure during the laminating procedure which will make the decor more realistic. Press plates with structure or structure foils are frequently used when manufacturing such a laminate. A negative reproduction of the structure in the press plate or the foil will be imprinted into the laminate during the laminating procedure.
One panel format which is rather common on the market is approximately 1.2×0.2 m. This format, and formats close to this, have the advantage that a package of a number of such panels is easy to handle and will be possible to transport in most cars. The format is still large enough to reduce the time used for installation of the panels. Formats much larger would be difficult to transport and formats much smaller would consume more time during installation.
As said earlier, the decor of these panels most often depicts products like wood and minerals. The wood decor may for example be constituted by a number of wood blocks arranged in parallel rows on each panel. Popular designs show two and three parallel rows of such blocks on each panel. It is important to design the decor so that the panels will give a continuous impression when installed. The design of parallel row wood block pattern can be designed as shown in WO 9301378 and the result on an installed floor will make the short side edges more or less disappear.
The decor of these panels are most often printed on a continuous web by means of one or more printing cylinders. It is understood that these printing cylinders have a repetition frequency which is depending on the diameter, or actually the circumference of the cylinder. The cost of such a cylinder is of course depending on the size i.e. diameter of the cylinder. A longer repetition distance will also add problems with format change of the decor. The format of the decor is caused by the different treatments the decor web is subjected to such as the printing itself, changes in moisture and temperature, impregnation, curing and the laminating process.
Another popular decor is when each panel depicts a wood plank or in other words that the panel has a decor which gives the impression that it is a single piece of solid wood. This makes it different from the blocked wood design described above. Here the length of 1.2 meter or so, seems a bit short and it would be more pleasing to the eye to have a panel length of 2 meters or more. However, this would give other problems like the transportability, the printing cost and the decor matching discussed above.
It has for a long time been a great need to be able to manufacture a decorative thermosetting laminate with a decor pattern with a surface structure as life like as the decor reproduced.